Is winter worse for stressed fish? The consequences of exogenous cortisol manipulation on over-winter survival and condition of juvenile largemouth bass

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“…The low pond survival rate of grass carp was probably influenced primarily by low temperatures (Hurst, 2007;Binder et al, 2015). Grass carp tolerate a range of water temperatures from 0 to 33°C (Cudmore & Mandrak, 2004).…”

“…Under pond conditions, fish not only lose weight, but are in relatively poor condition when water temperatures begin to rise (David, 2006). The weakened fish are vulnerable to bacterial and fungi contamination and disease (Binder et al, 2015) and are not suitable for further aquaculture production. According to available published data the immune system is non-functional in grass carp for most of the overwintering period.…”

“…Grass carp may be attacked by mammalian or even insect predators-dragonfly larvae (Akpona et al, 2015). Injured juveniles may also contract secondary bacterial and fungi infection and disease (Binder et al, 2015). Rearing in RAS positively affected survival rate and health and provided protection against predators.…”